Posted: 11/14/06
Heating system upgrades could save money
Board approves
preliminary study for middle/high school
By David Heiller
Argus News Editor
ISD #299 could save about $40,000 a year by making changes in its heating and cooling system at the middle/high school.
Thatís the opinion of two engineers from Michaels Engineering of La Crosse, WI, who made a proposal to investigate the system at a special board meeting on November 8.
The board approved a $5,900 contract with Michaels to do the investigation. Engineers Jeffrey Ihnen and Jack Bly said they didnít know what the cost of the actual project would be, but they both said it would pay for itself within four years.
Most of the energy savings would come by modifying one of the two 100 hp motors which operate the well loop and building loop of the geothermal system.
The building loop motor runs almost continuously, which costs an estimated $40,000 annually, Ihnen said.
The two motors can be reduced to one that has a variable speed drive, Ihnen told the board during a 45-minute Power Point presentation. It would save ìat least $3,000 per month in pumping energy alone,î he wrote in his proposal to the board.
The initial study, which will be done this year, will also look at pump energy consumption, piping reconfiguration, converting the system to one loop, removing the loop pump, and installing isolation valves on the heat pumps.
After the study is done, Michaels will draft a proposal on the design phase, which will outline the scope of the work that needs to be done. They will have a good estimate of the final price at that time, engineer Jack Bly said. He didnít give a dollar figure.
Board member Chuck Schulte asked Bly and Ihnen what they thought of the schoolís heating and cooling system, which was installed when the building opened in 2002.
Bly said the system was over-designed, and is more than the 144,000-square-foot building needs. He called it a good system that has every scenario built into it.
Board member Barb Hurley said that point was discussed when the building was planned. She said the system was built to last forever, and also to accommodate an addition or another school being located nearby.
Board member Naomi Fruechte said that with a $3,000 per month energy savings, the project would pay for itself.
ìWe could be in the two year payback range,î Ihnen responded. He later said that it would not be longer than four years. ìThis is about as high a confidence as we can have in any building,î Ihnen said.
Air quality would not be affected, Ihnen said in response to a question from board member Joyce Knutson. Michaels is proposing changing the ventilation controls from 500 parts per million of CO2 to 1,200, which Ihnen said is the upper range for adequately ventilated spaces. This would save ventilation heating and cooling energy because less outside air would be needed and therefore less motor use and electicity consumption.
Schulte said he has heard complaints that some rooms get too hot in the building.
Maintenance supervisor Bill Woolley said that local set points in classrooms are disabled. ìI reset the set points immediately if they let me know itís uncomfortable,î he said.
Schulte also asked if the study could look at fan noise in the auditorium. He said fans are shut off there during performances, and the room gets stuffy. Ihnen said they would look at that.
How it works: The schoolís heating system has 392 wells consisting of black PVC pipe that go 150 feet into the ground. A mixture of glycol and water is pumped through the pipes to acquire the constant temperature of the earth, which is between 53 and 57 degrees. The liquid is pumped through a heat recovery unit which heats or cools the air to the appropriate temperature.
Election canvassed
In other business, the board approved the school board election results. The four-year terms are for Charlie Wray (2,012 votes), Naomi Fruechte (1,980), Michelle Werner (1,922), and Matt Hendel (154 write-in votes). The two-year term is for Joyce Knutson (2,302).
Werner and Hendel will start on January 1. Schulte and Mary Frank will leave the board at that time.
Personnel business
The board also approved hiring Nora Bengtson as a part-time middle/high school special educational assistant at $9.49 per hour.
Jackie Johnson was hired as assistant gymnastics coach at $2,173.80.
Frank and Wray were absent from the meeting.
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